Grimm's Hatchery

I am trying to find out if anyone knows exactly how many creatures you need to feed all at once in order to have enough points for the last level. I can manage to get to the last level but I run out of time and I hardly have any points to buy the creatures in this level never mind take back the castle.

It's easier to win on the easy level simple because there are more days to complete the goal. I have won on medium and insane multiple times without buying the last hatchery. If I still feel like playing I choose to keep the farms and then I earn enough money to buy the last hatchery and purchase pets.

The strategy I use is to have 10 of each animal minus the magic geese and the red dragonfly's in the 3rd hatchery. I have 10 purple dragons, 10 ruby gryphons and 10 icebirds. I click on all the eggs I can and when I finally run out of time I simply sell all the eggs. It's a much safer bet than trying to hatch eggs and selling the resulting pet. In most cases you'll get more money from selling the eggs over hatching and selling pets.